Building panels—specifically water pervious ceiling panels—have a tendency to become stained when exposed to water. Water may contact a building panel in the form of droplets that originate from condensation or a leak on pipes and ductwork that are located in the space above the ceiling. The water can drip onto the backside of the building panel and migrate to the visible appearance side of a panel. Staining can occur because the water can carry off contaminants from surfaces it contacts and, often, because the water droplets migrate through the building panel and leach tannin from recycled newsprint or other plant based cellulose materials, as well as inorganic staining agents, from other components used in the tile composition bringing such staining agents to the front surface of the panel.
Previous attempts at preventing the formation of stains in building panels included adding a back coating to the building panel. However, such previous attempts provide only temporary resistance to staining as water can still migrate through other areas of the building panel resulting in the need for premature replacement of the ceiling panel before reaching the fully the intended life-span of the building panel. These previous attempts also fail to address the substantial risk of sagging within the body of building panel after being exposed to water from one or more leaks and/or condensation. Thus, there exists a need for an improved stain-resistant building panel that can extend the life-span of the building panel by prolonging the formation of stains on a building panel after exposure to water as well as exhibit superior sag resistance after being exposed to water.